Yamaha DTXpress/DTXplorer/DTXtreme

I use a TubeWorks 300watt Bass Head with a TubeWorks 4x10 speaker cabinet, 
and  a Roland KC-500 Keyboard Amp. I have used the Roland by itself, the 
Tubeworks by itself, and both together. The TubeWorks 4x10 and Bass Head by itself 
sound better than the Roland by itself. I have used a Guitar Amp before and they 
sound really crappy because they cannot handle the bottom end.

Claudio Ortiz